How do you calculate externally Studentized residuals in R?

How do you calculate externally Studentized residuals in R?

Types of residuals

  1. Externally studentized residuals ( rstudent in R): ti=ei^σ(i)√1−Hii∼tn−p−2.
  2. The quantity ˆσ2(i) is the MSE of the model fit to all data except case i (i.e. it has n−1 observations and p features).
  3. Numerically, these residuals are highly correlated, as we would expect.

How do you calculate Studentized residuals in Excel?

How to Calculate Standardized Residuals in Excel

  1. A residual is the difference between an observed value and a predicted value in a regression model.
  2. It is calculated as:
  3. Residual = Observed value – Predicted value.

What is a large cook’s distance?

Definition. Data points with large residuals (outliers) and/or high leverage may distort the outcome and accuracy of a regression. Cook’s distance measures the effect of deleting a given observation. Points with a large Cook’s distance are considered to merit closer examination in the analysis.

What is the difference between standardized and Studentized residuals?

Note that the only difference between the standardized residuals considered in the previous section and the studentized residuals considered here is that standardized residuals use the mean square error for the model based on all observations, MSE, while studentized residuals use the mean square error based on the …

How do you plot standardized residuals in Excel?

Click the “Insert” tab, choose “Insert Scatter (X,Y) or Bubble Chart” from the Charts group and select the first “Scatter” option to create a residual plot. If the dots tightly adhere to the zero baseline, the regression equation is reasonably accurate.

What is the sum of the leverage H I I?

The leverage h i i is a number between 0 and 1, inclusive. The sum of the h i i equals p, the number of parameters (regression coefficients including the intercept).

How is leverage used in a regression analysis?

1 The leverage merely quantifies the potential for a data point to exert strong influence on the regression analysis. 2 The leverage depends only on the predictor values. 3 Whether the data point is influential or not also depends on the observed value of the reponse y i.

How to calculate the leverage of an x value?

The sum of the \\(h_{ii}\\) equals p, the number of parameters (regression coefficients including the intercept). The first bullet indicates that the leverage \\(h_{ii}\\) quantifies how far away the \\(i^{th}\\) x value is from the rest of the x values.